Chlamydia
Avian chlamydiosis is a bacterial disease caused by Chlamydia psittaci, which is carried commonly by birds. Humans can catch the disease by breathing in dust containing dried saliva, feathers, mucous and droppings from infected birds. Infection in humans is called psittacosis and causes flu like symptoms.
Bird treatment is usually with oral doxycycline antibiotic. Since the doxycycline only kills the Chlamydia organisms when they are active and dividing, and they may become dormant, or cease being active for a period, the drug must be used for a minimum of 45 days.